Air pollution kills over 2 million people each year

Hold your breath. Air pollution kills more than 2 million people worldwide every year.

By using climate models to simulate what air pollution was like in 1850 and 2000, Jason West at the University of North Carolina at Chapel Hill and his colleagues have estimated its effect on current death rates. The team links ozone to about 470,000 deaths per year from respiratory disease; increases in particulates – fine particles that penetrate the lungs – are behind 2.1 million deaths from heart and lung disease.

“These shocking figures are so high because many of these deaths occur in Asia, where population numbers are high and where air pollution has increased markedly in recent years,” says Frank Kelly of King’s College London.

The study also assessed the contribution of climate change, which can exacerbate the effects of air pollution in various ways, such as changing humidity, which affects the reaction rates that determine whether pollutants form and how long they last. However, climate change was found to be linked to just 3,700 of the annual deaths from air pollution.

Although there is a degree of uncertainty associated with the estimates, the results are comparable with previous studies.

“The figure of 2.1 million does not differ greatly from the estimate reported last year by the World Health Organization, suggesting they are in the right area,” says Kelly.

“Premature mortality associated with poor air quality is likely to become the world’s top environmental challenge, even exceeding water and sanitation,” he adds.